[BAEL-2048] Spring Data JPA multiple databases article

spring-data-jpa/src/test/java/org/baeldung/persistence/service/JpaMultipleDBIntegrationTest.java

@@ -0,0 +1,97 @@
+package org.baeldung.persistence.service;
+
+import org.baeldung.config.ProductConfig;
+import org.baeldung.config.UserConfig;
+import org.baeldung.persistence.multiple.dao.product.ProductRepository;
+import org.baeldung.persistence.multiple.dao.user.PossessionRepository;
+import org.baeldung.persistence.multiple.dao.user.UserRepository;
+import org.baeldung.persistence.multiple.model.product.Product;
+import org.baeldung.persistence.multiple.model.user.Possession;
+import org.baeldung.persistence.multiple.model.user.User;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.dao.DataIntegrityViolationException;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.transaction.annotation.EnableTransactionManagement;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.Collections;
+import java.util.Optional;
+
+import static org.junit.Assert.*;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration(classes = { UserConfig.class, ProductConfig.class })
+@EnableTransactionManagement
+@DirtiesContext
+public class JpaMultipleDBIntegrationTest {
+
+    @Autowired
+    private UserRepository userRepository;
+
+    @Autowired
+    private PossessionRepository possessionRepository;
+
+    @Autowired
+    private ProductRepository productRepository;
+
+    // tests
+
+    @Test
+    @Transactional("userTransactionManager")
+    public void whenCreatingUser_thenCreated() {
+        User user = new User();
+        user.setName("John");
+        user.setEmail("john@test.com");
+        user.setAge(20);
+        Possession p = new Possession("sample");
+        p = possessionRepository.save(p);
+        user.setPossessionList(Collections.singletonList(p));
+        user = userRepository.save(user);
+        final Optional<User> result = userRepository.findById(user.getId());
+        assertTrue(result.isPresent());
+        System.out.println(result.get().getPossessionList());
+        assertEquals(1, result.get().getPossessionList().size());
+    }
+
+    @Test
+    @Transactional("userTransactionManager")
+    public void whenCreatingUsersWithSameEmail_thenRollback() {
+        User user1 = new User();
+        user1.setName("John");
+        user1.setEmail("john@test.com");
+        user1.setAge(20);
+        user1 = userRepository.save(user1);
+        assertTrue(userRepository.findById(user1.getId()).isPresent());
+
+        User user2 = new User();
+        user2.setName("Tom");
+        user2.setEmail("john@test.com");
+        user2.setAge(10);
+        try {
+            user2 = userRepository.save(user2);
+            userRepository.flush();
+            fail("DataIntegrityViolationException should be thrown!");
+        } catch (final DataIntegrityViolationException e) {
+            // Expected
+        } catch (final Exception e) {
+            fail("DataIntegrityViolationException should be thrown, instead got: " + e);
+        }
+    }
+
+    @Test
+    @Transactional("productTransactionManager")
+    public void whenCreatingProduct_thenCreated() {
+        Product product = new Product();
+        product.setName("Book");
+        product.setId(2);
+        product.setPrice(20);
+        product = productRepository.save(product);
+
+        assertTrue(productRepository.findById(product.getId()).isPresent());
+    }
+
+}